- Naba Raj Pandita, b, c,
- Jan Mulderb,
- Sarah Elizabeth Halea,
- Vegard Martinsenb,
- Hans Peter Schmidtd,
- Gerard Cornelissena, b, ,
- https://doi.org/10.1016/j.scitotenv.2018.01.022
- Get rights and content
Open Access
Highlights
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Soil limitations (moisture, nutrients, acidity) were manipulated one by one to find out why biochar improved crop growth.
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Biochar addition increased soil pH, plant available P, K and soil moisture retention in this weathered Nepalese soil.
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The biochar effect on plant growth was mainly due to alleviation of nutrient stress.
Abstract
We
studied the role of biochar in improving soil fertility for maize
production. The effects of biochar on the alleviation of three potential
physical-chemical soil limitations for maize growth were investigated,
i.e. water stress, nutrient stress and acid stress. Experiments involved
soils with two dosages of biochar (0.5% and 2% w:w), as well as ones
without biochar, in combination with four different dosages of NPK
fertilizer, water and lime. Biochar was produced from the invasive
shrubby weed Eupatorium adenophorum using flame curtain kilns.
This is the first study to alleviate one by one the water stress,
nutrient stress and acid stress in order to investigate the mechanisms
of biochar effects on soil fertility.
Biochar addition
increased soil moisture, potassium (K) and plant available phosphorous
(P-AL), which all showed significant positive relationship (p < 0.001)
with above ground biomass of maize. However, biochar was much more
effective at abundant soil watering (+ 311% biomass) than at
water-starved conditions (+ 67% biomass), indicating that biochar did
increase soil moisture, but that this was not the main reason for the
positive biomass growth effects. Biochar addition did have a stronger
effect under nutrient-stressed conditions (+ 363%) than under abundant
nutrient application (+ 132%). Biochar amendment increased soil pH, but
liming and pH had no effect on maize dry biomass, so acidity stress
alleviation was not the mechanism of biochar effects on soil fertility.
In
conclusion, the alleviation of nutrient stress was the probably the
main factor contributing to the increased maize biomass production upon
biochar addition to this moderately acidic Inceptisol.